Machine for grinding and polishing round bars



July 31, 1955 H. A. RIPPL 2,756,547

MACHINE FOR GRINDING AND POLISHING ROUND BARS Filed March 3, 1955 3 Sheets-$heet l R. N @Q E Q lllL.r|| II IN V EN TOR. /Aeaw ,4. AmpL C |n:: l .TV-.

, M14/Www Arrows/5X5 H. A. RIPPL July 31, 1956 MACHINE FOR GRINDING AND POLISHING ROUND BARS Filed March 3, 1955 3 Sheets-Sheet 2 INVENTOR. #wow /LR/PPL wg@ Q 56 53 42 4 1 l f 1 I 44d FG Arran/vers July 3l, 1956 H. A. RIPPL. 2,756,547

MACHINE FOR GRINDING AND POLISHING ROUND BARS Filed March 3, 1955 3 Sheets-Sheet 3 9 IN V EN TOR.

#Amm A /P/PPL Arron/v YS MACHINE FOR GRINDING-AND PLISHING ROUND`r BARS Harold A. RippLBerea, Ohio Application March '3, 1955,5Serial N0.492,016

' '13 Claims. (c1. 51- 14z) This invention relates to improvements in machines for grinding and polishing round bars. lt may be employed to grind oif a small amount of metal for dimensie-ning the diameter of the bar accurately Aand/or for impartir-.g a high polish to the surface of the bar.

To accomplish these purposes I employan endless abrasive belt which is caused to overhang and contact the work, which belt is mounted upon y'a carriage that travels back and forth lengthwise ofthe work, the latter being rotated about its axis. The 4machine may be used to nish round bars of large or small diameter and of considerable length, in other words of anylength which can be handled conveniently, it being appreciated that bars or 30 feet long and of 6 or 8 inchesdiameter are extremely heavy. i

One of the objects of the invention is theprovision of a machine of the character statedvhaving va capacity of handling round bars of any size, accurately lnishing them and imparting to them a high polish.

Another object is the provision of means `for reciprocating the carriage at a selected speed.

Another object is the provision of means for quickly and easily swinging back the 'abrasive or polishing belt to permit ready removal of the finished work and the placing in position of new unfinished work.

Another object is the provision of means for canting or cooking the belt soL that its surface will lie at a small angle to the length of the work instead of traveling flat upon the work.

A further object is the provision of controls operable from either end of the machine for starting, stopping and reversing the travel of the carriage manually or for doing the same thing automatically.

Other objects and features of novelty will appear as l procee with the description of that embodimentof the invention which7 for the purposes of the "present application l have illustrated inthe accompanyingdrawings, in which: n

Fig. l is'a plan view partially broken away of a machine embodying the invention;

Fig. 2 is an end elevational view'showing the abrasive belt in operative position;

Fig. 3 is a fragmental view similarto Fig. 2 but with they carriage and associated parts removed;

Figs. 4 and 5 are sectional viewstaken substantially on the linesd-#l and 5-#5 of Fig. vr2;

Figo .is a fragmental end elevational'view'showing the belt idler adjusted -to cause the belt to engageffthe work through 'a very small angle kor sector of` its-surface;

Fig. v7 is a plan-view illustrating the-means vforadjusting the work supporting rollers toward or away from each other;

Fig. 8 is a fragmentalview-similar-to Fig. 6 but showing the supporting rollers yrelatively lclose together-:for supporting and rotating work lof=relatively-small-diam eter;

Fig. 9 is a fragmental end View showing theposition nited States Patent() ricc o-f the belt carrying arm when the belt kis swung up away from the work;

Fig. lOis a sectional view of a mo'died formof belt idler which may Y-be employed in connection with the t invention; yand Fig. ll is a fragmental detail elevational view showing switches for reversing the direction of ltravel ofthe carriage.

In `the drawings ll have-illustrated a heavy machine frame embodying longitudinal channels 12 and transverse channels 13 welded or'otherwise fastened together and mounted uponaconcrete or other base vstructure 14. The frame may also include longitudinal I-beams 15 mounted upon and secured to the channels 12 and transverse end beams 16 of similar'cross section. Intermediate the ends of the frame there' are a plurality of transverse elements 17 which are preferably of thesame longitudinal dimensions as the end members 16 andmay be of l-bearn cross section. The base of the machine is therefore very Vrigid and strong and will support very heavy work `without undue flexure. Supported partly upon alongitu'dinall-beam l5' and partly upon the transverse'bealns 16 and 17 there are a series of heavy plates 18, Veach of which supports a pair of pillow blocks v19 that are mounted above transverse slots 20. These pil- Ilow blocks are slidable transversely of the machine and -may be locked in selectedv positions by' bolts 21 extending through the ends fof th'epillow blocks and through the lslots 20.

Two parallel longitudinal shafts 23 are rotatably car- :ried in the pillowblocks 19. When the bolts 21 are loosened these shafts vmay be imove'd "toward or away from each other, or one may be'held stationary while the other ismoved toward and away from it. A convenient means for accomplishing this movementnmay comprise a Vtransverse 'screw 24 at each end `of the ,'r'nachine, each screw 'having oppositelydirected threads running in internally threaded sleeves 25 the shaft being rotatable by'rneans of a crank 125 to turn in a bearing block Z6 and being held by collars 27 against axial movement in 'either direction. The sleeves 25 have upwardly 'offset portions '28 boredto receive the shafts 23. Cranks 'should 'be' turned like amounts in one direction or the other to cause the shafts '23 to rnoveftoward or gaway from each other, and when the desired adjustment has 'been accomplished the bolts 21 for all pillow blocks are tightened to give firm bearings for the shafts.

Pair of 'rollers 30 are secured to shafts 23 spaced along the lengths of the shafts. The rollers may be disposed directly opposite each other, as in Fig. l, or they may be oiset asin Figs. 7 and 8. The advantage of the latter arrangement is Athat work of small diameter maybe supported and frictionally driven with the upper surface-of the work, indicated at W, always above the vupper surface of the rollers. The shafts 23 and rollers 30 are driven in the same direction, clockwise as illustrated in the drawings. lThe illustrated means for so driving kmounted round bars 40 vwhich together constitute a track that extendstheifull `lengthof the machine. These kbars arepreferably welded to the frame, andthe latter mayhaveendfplates 41. againsbwhich thetrack members abut. A carriage C is mounted to run on the track barsV 40. The carriage comprises a rigid frame in which are journaled transverse shafts 42 upon the ends of which are secured wheels 43 of quarter-round contour. The weight of the carriage thus tends to hold it against possible movement transversely of the track, and the arrangement also continuously compensates for wear.

The end plates 44 on the carriage carry brackets 45 which receive the ends of a chain 46. This chain runs over Sprockets 47 and 47 mounted at the ends of the machine frame and through windows d in the end ibeams 1.6.l By means of this chain the carriage may obviously be caused to travel from one end of the machine to the other in either direction. The chain is driven by the sprocket 47 which is keyed to a short shaft 49 that may be driven by suitable means, as by a belt 50 from the output shaft 51 of a multispeed transmission 52, the latter being controlled by a shift lever 53 somewhat in the manner of an automobile transmission. The transmission in turn is operated by a reversible electric motor 54.

By manipulation of the gear shift lever 53 the carriage may be driven at a selected speed in both directions, or at a selected speed during active travel of the carriage, and at high speed during return travel. The transmission 52 could of course include a reverse gear, but reversing the eld of motor 54 is the preferred means for changing the direction of travel.

The carriage C includes a pivot bar 56 which is set well down in the carriage frame and supported in end bearings 57 attached to the end plates 44 of the carriage frame. On this pivot barthere is pivotally mounted a platform 50, the platform having near one end a pair of depending lugs 59 that are perforated to receive the bar 56. The forward end of the platform carries a threaded stop 60, the lower end of which is adapted to bear against a block 61 which forms part of the carriage frame and limits the extent to which the forward end of the platform may descend. In order to enable the operator to manipulate the stop 60 conveniently, I provide a socket wrench 62 with a long handle which ts over the hex head of the stop screw and projects upwardly to a position above other equipment on the carriage.

On the platform there is hinged at 64 a base plate 65 to whichjis secured an electric motor 66. At the end opposite the hinge 64 the base plate carries a pivoted nut 67 through which extends an adjusting screw 68 the lower extremity of which is connected with the platform 58. By manipulating the screw 68 the base plate 65 may obviously be adjusted up or down with respect to the platform, this adjustment being for the purpose of regulating the tension vof the abrasive belt, as will presently appear.

On the shaft of motor 66 there is a pulley 70 over which runs an abrasive belt 71, the outer surface of the belt being impregnated with abrasive of a selected grade. Alternatively, the outer surface of the belt may be constituted of buifing material.

To the forward side of the carriage frame there is welded or otherwise secured an upstanding at post 72 which forms a support for a forwardly projecting rectangular tubular element 73. At its rear end this element comprises a transverse plate 74 which is connected to post 72 by a horizontal bolt 75. At the top and bottom ends of plate 74 there are rearwardly extending lips 76, through which screws 77 are threaded. Obviously if the bolt 7S and the screws 77 are loosened tubular element 73 may be canted or cocked around the bolt 75 to a selected extent and the screws 77 adjusted to hold the element in that position. Telescoping within the tubuiar element 73 there is a second element 7S which carries at opposite sides locking screws 79 that project through slots 80 in the tubular element. Elements 73 and 78 together constitute a forwardly projecting arm upon the extremity of which is rotatably mounted an idler pulley 81 in line with pulley 70, the idler 8l forming the forward support for the endless belt 71.

The platform forward of the pivot 56 with the forwardly projecting arm 73, 78 carried thereby is slightly over-balanced by the platform rearwardly of pivot 56 together with the motor 66 and its base 65. Means are provided to raise the rear part of the platform to overcome this over-balance and to thereby hold the belt 71 against the work. This means preferably consists of a caro. 83 rotatable upon a stub shaft 84 which is fixed within a bracket 05 secured to platform 58. To the cam there is attached an upwardly extending long handle S6. When this handle is swung up to the position of Fig. 9 the overbalance of the motor 66 and other parts to the right of pivot bar 56 throws the belt 71 upwardly away from the work. At such times the finished work can be removed readily and replaced by new work. Thereafter' the operator merely presses down on the outer end of handle 86 which pries the rear end of platform 5S upwardly to the Fig. l or working position, and locks it there. The screw stop 60 provides a iine adjustment which limits the extent to which the cam 83 may be manipulated for lowering the belt against the work. The telescoping adjustment of the parts 73 and 78 of the idler supporting arm constitutes an important feature of the invention inasmuch as this adjustment taken with the tensioning adjustment of the belt by means of screw 68 determines the sector or arc of the work contacted by the belt. This will be evident from a comparison of Figs. 2 and 6 of the drawings. A sheet metal cover S7 for the belt 71 may be provided and may be supported in any suitable manner, not shown.

In Fig. l0 l have illustrated a modified form of idler pulley 39 which is adapted to reduce bounce and chatter. lt is constructed of natural or synthetic rubber and is intlated through a tire valve indicated at 90.

The work W is rotated rather rapidly upon its axis by the pairs of rollers 30. To avoid any possibility of its being moved longitudinally I may provide stop means at one or both ends of the machine, such as the stop 91 shown at the left end in Fig. l.

The operation of the motor 54 to reciprocate the carriage C is controlled by limit switches 93, 94 located adjacent the front of the machine immediately above the bar 95, the latter being mounted to slide lengthwise in guides 96. The limit switches 93, 94 are adapted to be actuated by cams 97, 98, respectively, mounted on the bar 95. The cams and the actuating levers 99, for the switches 93, 94 are so arranged that when the bar 95 is shifted toward the left, as shown in Fig. l1, the switch 94 is closed and the switch 93 is opened. In this condition, the switch 94 completes a circuit to a relay for operating the motor in the direction necessary to move the carriage toward the left as the machine is viewed in Fig. 1.

The means for shifting the bar 99 lengthwise comprises two vertical levers 101 and 102 mounted on pivots 103 and 104 disposed near opposite ends of the machine frame. The lower ends of these levers are straddled by U-shaped brackets 105 which are pinned to the bar. Projecting forwardly and downwardly from the arm 73, 78 there is an abutment 106 which strikes the levers 101 and 102 as the carriage reaches the ends of its travel. The levers are thus swung from one position to the other, irnparting a sliding movement to bar 95.

When the carriage reaches the end of its travel toward the left for example, lever 101 is swung counterclockwise and shifts bar 95 to the right, causing the switch 94 to open, breaking the circuit to the relay for operating the motor in a direction to move the carriage to the left, and operating the switch 93 to close the contacts to a second relay,'which causes the motor to operate in the direction necessary to move the carriage to the right. Preferably, the switches 93, 94 are operated at the same time and the relay circuits interlocked so that only one relay can be energized at any given time.

A motor control panel is provided, which includes the relays for reversing the motor 54 as well as a disconnect switch for disconnecting the relays from the power supply for the motor 54. The motor control panel 107 also includes an off-on switch for starting and stopping the operation of the motor 35. The motor 54 may also be stopped by depressing a push button switch 108 mounted on the front of the machine.

Having thus described my invention, I claim:

1. In a machine for grinding and polishing round bars, a frame, a pair of parallel shafts supported therein, means for rotating said shafts in the same direction, a series of rollers mounted upon and driven by each of said shafts, said rollers constituting the support for the work and constituting also means for rotating it frictionally, a track parallel to said shafts, a carriage movable back and forth upon said track, a pulley on said carriage, a counterbalanced cantilever arm mounted upon said carriage extending above said rollers and the work mounted thereon, an idler supported upon the free end of said arm, an abrasive belt running over said pulley and idler, the lower run of which is adapted to bear upon the work, means for depressing the free end of the arm to a selected extent whereby the arc of contact between the work and said belt may be varied and means for reciprocating said carriage and driving said pulley.

2. A machine for grinding and polishing round bars substantially as defined in claim 1, comprising means for adjusting said shafts relatively toward and away from each other to properly support and rotate work of different diameters with the upper surface of the work extending above the upper surfaces of said rollers, said means comprising a transverse screw shaft cooperating with the mountings for at least one of said parallel shafts for moving the latter shafts relatively toward or away fro-m each other, and common driving means for said shafts operable in all positions of shaft adjustment.

3. A machine for grinding and polishing round bars substantially as defined in claim 2, wherein the rollers of each pair are axially offset from each other and extend radially from the shafts a distance less than the minimum distance between the shafts, whereby the rollers of each pair are adapted to overlap for supporting relatively small bars with their upper surfaces above the upper surfaces of the rollers.

4. A machine for grinding and polishing round bars substantially as defined in claim l, comprising means for adjustably cocking said idler through a small angle to control the angle of contact of the abrasive belt upon the work being ground and polished.

5. A machine for grinding and polishing round bars substantially as defined in claim 1, comprising means for adjusting the length of said arm to cause said idler to bear upon or override the curved surface of the work and thereby combine with said means for depressing the free end of the arm to vary the action of the belt.

6. A machine for grinding and polishing round bars substantially as defined in claim 1, comprising a motor having a shaft on which said pulley is mounted, a hinge mounting for said motor on the side thereof toward said idler, whereby the weight of the motor tends to tension said belt, and means on the side of the motor remote from said idler for tilting the motor about its hinge mounting.

7. A machine for grinding and polishing round bars substantially as defined in claim 1, wherein said means for reciprocating said carriage comprises a variable transmission and a shift lever controlling said transmission.

8. A machine for grinding and polishing round bars substantially as defined in claim l, wherein said means for reciprocating the carriage comprises means at the ends of the carriage travel for automatically stopping the carriage and reversing its direction of travel.

9. A machine for grinding and polishing round bars substantially as dened in claim 8, wherein the means for reciprocating the carriage comprises a reversible electric motor, and limit switches at the ends of the carriage travel for reversing the direction of current through said motor.

l0. A machine for grinding and polishing bars substantially as defined in claim 1, wherein said carriage reciprocating means comprises a reversible electric motor, drive means powered by said motor for moving said carriage in opposite directions, and control means comprising a rod parallel to said shafts slidable lengthwise and operable from either end thereof, an electric circuit for said motor, and switch means in said circuit actuated by said rod.

1l. A machine for grinding and polishing round bars substantially as defined in claim 10, comprising a projecting abutment on said carriage, levers spaced lengthwise of the machine disposed to be contacted by said abutment as the carriage nears the ends of its travel, and means actuated by the movement of said levers for shifting said rod lengthwise.

12. A machine for grinding and polishing round bars substantially as defined in claim l, comprising means for adjusting the length of said arm to cause said idler pulley to move toward or away from the work in combination with means for controlling the pressure exerted by the belt against the work.

13. A machine for grinding and polishing round bars substantially as defined in claim 1, wherein said carriage comprises a platform mounted on a pivot disposed parallel to the direction of carriage travel, and wherein the means for driving said pulley comprises an electric motor on the shaft of which said pulley is mounted, said motor being hingedly mounted on the platform on the side of said pivot remote from the work, the weight of the' motor tending to tension said belt and tending to swing the rear end of the platform down for raising the belt away from the work, and cam means for raising the platform to swing belt down to operative position.

References Cited in the file of this patent UNITED STATES PATENTS 432,144 Muncaster July 15, 1890 482,947 Hope Sept. 20, 1892 492,095 Medart Feb. 21, 1893 871,323 Clemons Nov. 19, 1907 980,052 Blevney et al. Dec. 27, 1910 1,888,589 Egnor Nov. 22, 1932 1,995,382 Fenton Mar. 26, 1935 2,142,669 Carpenter Jan. 3, 1939 

